This invention relates generally to ovens useful for cooking or heating food products and, more particularly, to ovens such as may be used in the bakery industry to more evenly bake one or more racks of food products.
In the commercial baking industry, it is common to employ baking ovens that have a chamber or oven cavity sized sufficiently large to receive two tall racks or carriages, each containing multiple layers of a food product to be baked, in a single load. For example, a typical or standard baking rack may have provision for 20 or more cake or food trays each measuring 18 by 26 inches. Heating of the food product in such a baking process is typically accomplished via an indirect heat exchanger with heat supplied via a natural gas or oil burner or one or more electric heating elements.
Many convection ovens are equipped with fans capable of moving heated air throughout the baking chamber at various velocities. Normally, such ovens are designed to provide a rapid distribution of heated air over food products which have been placed on pans stacked one above the other. Unfortunately, the distribution of heated air in such ovens is not always as uniform as may be desired. As a result, food products arranged on a single rack and being cooked, e.g., baked, in such an oven may cook at uneven speeds. As a result, particular food products of a single rack can be cooked in an undesirable fashion, such as to various degrees of doneness and coloring, for example.
In an effort to improve such cooking results, ovens with rotating pan racks have been utilized. Large commercial ovens often have a large front door that extends from the floor to a height of about 80 inches and are sized sufficiently large as to permit the baking of two standard baking racks in a single load. Typically, the food-carrying racks are wheeled into the oven and secured to a mechanism that rotates the racks individually or as a pair, while the cooking process proceeds. In accordance with different oven designs, particular rack-rotation mechanisms operate to lift the rack(s) from the oven floor while in other oven designs the rack(s) may remain on the oven floor during rotation.
Further, the various racks produced by different manufacturers may be of different design and construction. Thus, typical rack-rotating ovens may require special modification or adaptation in order to work in the desired manner with racks of particular design. As a result, the use of such ovens may have undesirably increased costs associated therewith.
While such ovens may provide or result in certain improvements in cooking operation and results, such ovens are also typically subject to certain or various shortcomings or limitations. For example, such units generally require more room to permit rack rotation. Further, the inclusion of a rack rotation mechanism and associated power drive can undesirably increase unit costs as well as increase maintenance costs such as due to the number and magnitude of moving parts included therewith.
One approach directed to solving or reducing at least some of these problems or concerns is disclosed in U.S. Pat. No. 4,779,604, issued Oct. 25, 1988. This patent discloses a baking oven which includes a baking chamber and has air channels extending at both sides of the baking chamber as well as over the height of the baking chamber from top to bottom. The air channels are separated from the baking chamber by partition walls having provided therein air flow openings formed by horizontal slots. As disclosed, heated air is blown in alternating directions into the baking chamber by means of a blower such as by way of reversing the sense of rotation of the blower.
Unfortunately, the inclusion and reliance on reversible blowers has associated with it a number of complications or shortcomings. For example, reversible blowers require the inclusion of an appropriate brake mechanism to permit the direction of blowing to be reversed. Further, the subjection of a blower to repeated or ongoing stoppages and reversals can be undesirably hard on a blower motor and can lead to an increased frequency of breakdowns, needed repairs or maintenance downtime.
As a result, there is a continuing need and demand for improved oven assemblies and associated or related methods of operation for the cooking of food products such as to produce or result in even heat energy distribution within the cooking chamber cavity.
A general object of the invention is to provide improved oven assemblies and associated or related methods of operation for the cooking of food products.
Another general object of the invention is to provide such oven assemblies and associated or related methods of operation for the cooking of food products such as to produce or result in even heat energy distribution within the cooking chamber cavity.
A more specific objective of the invention is to overcome one or more of the problems described above.
The general object of the invention can be attained, at least in part, through a specific oven assembly for the cooking of food products. Such specific oven assembly includes a cooking chamber. The cooking chamber is defined at least in part by at least two pairs of oppositely disposed first and second wall structures. Each of the wall structures includes at least one slot opening for the passage of air therethrough.
The oven assembly also includes a rotating valve. The rotating valve is in both heated air receiving communication and return air communication with a heat source. At a selected point in time, the rotating valve is in heated air distributing communication with the first wall structure and in return air communication with the second wall structure of only one of the two pairs of oppositely disposed first and second wall structures, such that heated air is passed through the at least one slot opening in the first wall structure into the cooking chamber and return air from the cooking chamber is passed through the at least one slot opening in the oppositely disposed second wall structure and to the rotating valve for return to the heat source.
The rotating valve is capable of rotation such that, at a subsequent selected point in time, the rotating valve is in heated air distributing communication with the first wall structure and in return air communication with the second wall structure of the other of the two pairs of oppositely disposed first and second wall structures.
The prior art has generally failed to provide large scale oven assemblies and associated or related methods of operation for the cooking of food products which produce or result in even heat energy distribution within the cooking chamber cavity in an as effective a manner as desired. Such shortcomings are particularly significant and noticeable in applications such as commercial bakeries and the like, for example.
The invention further comprehends a commercial baking oven assembly for the baking of food products. In accordance with one preferred embodiment of the invention, such an oven assembly includes a baking chamber defined at least in part by two pairs of oppositely disposed first and second wall structures. Each of the wall structures includes a plurality of parallel slot openings for the passage of air therethrough.
The oven assembly also includes a rotating valve. The rotating valve is in both heated air receiving communication and return air communication with a burner assembly. At a selected point in time, the rotating valve is in heated air distributing communication with the first wall structure and in return air communication with the second wall structure of only one of the two pairs of oppositely disposed first and second wall structures, such that heated air is passed through the plurality of slot openings in the first wall structure into the baking chamber and return air from the baking chamber is passed through the plurality of slot openings in the oppositely disposed second wall structure and to the rotating valve for return to the burner assembly.
The rotating valve is capable of rotation to be in heated air distributing communication with the first wall structure and in return air communication with the second wall structure of the other of the two pairs of oppositely disposed first and second wall structures, at a subsequent selected point in time.
The invention still further comprehends a method of operating an oven for the cooking of food products with even heat energy distribution. In such method, the oven includes a cooking chamber defined at least in part by at least two pairs of oppositely disposed first and second wall structures. In such an oven, each of the wall structures includes at least one slot opening for the passage of air therethrough. The oven also includes a rotating valve in both heated air receiving communication and return air communication with a heat source. A method, in accordance with one embodiment of the invention, includes passing heated air from the heat source through the rotating valve and through the slot opening in a first wall structure of one of the two pairs into the cooking chamber, and return air from the cooking chamber through the slot opening in the corresponding second wall structure and the rotating valve to the heat source. The rotating valve is rotated to pass heated air from the heat source through the rotating valve and through the slot opening in a first wall structure of the other of the two pairs into the cooking chamber, and return air from the cooking chamber through the slot opening in the corresponding second wall structure.
The invention yet still further comprehends a method of operating a baking oven for the baking of food products with even heat energy distribution. In such method, the baking oven includes a baking chamber defined at least in part by two pairs of oppositely disposed first and second wall structures. Each of the wall structures of the baking oven include a plurality of slot openings for the passage of air therethrough. The baking oven also includes a rotating valve in both heated air receiving communication and return air communication with a burner assembly. The rotating valve has a first state in which the rotating valve is in heated air distributing communication with the slot openings of one of the wall structures of a selected one of the pair of wall structures and in return air communication with the slot openings of the other of the wall structures of the selected one of the pair of wall structures. The rotating valve also has a second state in which the rotating valve is in heated air distributing communication with the slot openings of one of the wall structures of the other of the pair of wall structures and in return air communication with the slot openings of the other of the wall structures of the other of the pair of wall structures. A method, in accordance with one embodiment of the invention, involves rotating the rotating valve to sequentially alternate the rotating valve between the first and second states.
Other objects and advantages will be apparent to those skilled in the art from the following detailed description taken in conjunction with the appended claims and drawings.